The invention concerns a slitter for material in web form, especially webs of paper and cardstock, having a rotating pair of circular knives consisting of a lower cup knife and an upper disk knife which plunges into the web material when cutting, the one circular knife being disposed with its axis perpendicular to the line of movement of the web and the other circular knife being disposed with its axis at an angle to the line of movement of the web.
In a known slitter of this kind, the lower, cup knife is the one whose axis is perpendicular to the line of movement of the web, while the upper disk knife is disposed at a slight angle thereto. In cutting with such a slitter it has been found disadvantageous that due to the angular disposition of the upper knife the cut edge of the material is displaced laterally from its line for movement by the back of the upper knife plunging into the web of goods. This places a stress on the cut edge and results in a greater production of cutting dust.